CVE-2026-54465 websocket-driver: Memory exhaustion in HTTP header parser
A remote attacker can cause memory exhaustion and denial of service in applications using the websocket-driver library by sending excessive HTTP headers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54465?
CVE-2026-54465 is a medium-severity denial of service vulnerability in faye websocket-driver-ruby, published on 17 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.1, when websocket-driver is used to implement a WebSocket server on top of a TCP server using WebSocket::Driver.server() or to complement a WebSocket client, a peer can make a single connection consume an unbounded amount of memory by sending an HTTP request or response with a never-ending list of headers. This can lead to the receiving process running out of memory. This issue is fixed in version 0.8.1.
Weakness: CWE-770
Which versions are affected by CVE-2026-54465?
2 open source packages ship an affected version, including websocket-driver. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
websocket-driver RubyGems | All versions | 0.8.1 |
websocket-driver RubyGems | All versions | 0.8.1 |
Products include Faye Websocket-Driver.
How do I fix CVE-2026-54465?
Upgrade websocket-driver to 0.8.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-54465 being exploited?
There is no known exploitation of CVE-2026-54465 in the wild and no public exploit code.
Other vulnerabilities in faye websocket-driver-ruby
Sources
Also known as CLSA-2026-1790944051, DEBIAN-CVE-2026-54465, GHSA-8j3g-f24p-4mpw, MINI-fw6f-crwq-545w, MINI-jrjr-cc7r-pvxc, UBUNTU-CVE-2026-54465.